Bite The Bullet

Size Does Matter - Batteries (2000-03-12)

Size does matter when it comes to AEG batteries. And why not? It's only intuitive to even the most casual and non-engineering aligned observer to speculate that the bigger the battery, the more juice it will have. Additionally, the bigger the battery, the longer it will last and the less you'll have to change batteries in the middle of a heated skirmish!

Overlooked by most first-time airsoft enthusiasts, battery size should be a major consideration when you are shopping for your AEG. If you're likely to keep your AEG stock, then the consideration is not as large. "Why?" you ask. Well here's the low-down.

There are two things you use to measure a battery:
(1) It's voltage (7.2v, 8.4v, 9.6, 10v, and 12v)
(2) It's current (ranging anywhere from 600milliamps (mah) to 3300 milliamps or more

Typically you can
tell the voltage of a battery just by looking at the number of cells it
has. In the photo above, you'll see a large 2000mah battery comprised
of 8 individual cells (in 2 rows of 4). 8 celled batteries are 9.6v
and 7 celled batteries are typically 8.4v. There's also the smaller
type 7 cell battery (the yellow one in the photo) which are small type 8.4v
batteries. No rules govern custom batteries (eg. the red M4A1 custom
12v battery) but these are typically labeled accordingly.
Having defined these measurement criteria, here is what you need to
know. The higher the voltage and current, the higher speed the motor
will be able to generate in driving a high powered, upgraded spring, thereby
translating into higher FPS (feet per second of the BB). Higher
current also typically drives the motor faster thereby increasing rate of
fire. So going back to the first statement of why you should consider
the battery size of an AEG before you buy one? Simply that if you plan
to upgrade your AEG to a higher spring rate, you should consider buying an
AEG that can take a larger battery that's capable of generating the voltage
you need.
To give an example, let's look at the MP5A5. While a terrific
all-round performer, it is designed to accomodate a SMALL 600mah 8.4v
battery to drive it's EG700 motor and M90 spring. This is great if you
intend to keep the gun stock but once you upgrade the A5 to an M120 or
above, the SMALL battery simply cannot produce enough power to drive
the stiffer spring and the owner is often forced to carry a LARGE 1300mah
battery in a strap-on canvas battery bag to drive the upgraded spring (the
A5's front grip is only just large enough to hold the SMALL battery).
The situation is even more severe in the MP5K and PDW series AEGs which
utilize the even smaller 7.2v stick type battery.

So what?

Well most airsofters simply resent having to
carry an external battery since it ruins the authenticity of the gun.
Heck if you didn't mind the external battery bag, you could carry as large a
battery as you need. The classic example is the Vulcan where I've seen
some folks carry car batteries on their backs to drive these monsters!
For some who have been forced down this route with the more compact AEGs but
can't stand the sight of the external battery bag, many methods have been
derived to hide the large battery, such as by storing it in a gutted
magazine, gutted scope, and other black metallic boxes attached to the
gun. These custom solutions often require the owner to buy individual
power cells and soldering them together in a fashion that fits the intended
storage compartment (whether it be in the scope or the mag, or any other
contraption).

The table above only represents the typically
needed battery sizes. For some guns like the M4A1 and AUG, custom
sized batteries are available to drive the higher spring rates. These
custom batteries typically have a short life span with higher voltages, but
benefit from their ability to fit inside the stock storage compartment of
the AEG. For example, the custom 12v 600mah battery for the M4A1 can
power the M150 upgrade and fits snugly in the front foregrip. Lifespan
is limited to 600 rounds or so. Larger batteries obviously last much
much longer.

As you can probably derive from this
information - if you're planning to upgrade your weapon, it's best to get an
AEG that has room to store a large battery. That's why AEGs like the
AK47, M16A1/A2, G3A3/SG1, and MP5A4/SD5 make such great upgrade
candidates. Their fixed stock offer generous amounts of space for a
large battery. In the case of the SG1, you can even deepen the stock
(via a small modification) to fit a EXTRA LARGE 9.6v battery for super power! One thing you should also be aware of is that ANY spring
upgrade will require an EG700 motor or above. The EG560 simply does
not have enough power to drive stiff springs.

If you're thinking to yourself that
"Hey, I don't need to upgrade anyways", here's another
thought. You can increase the ROF of a stock AEG simply by moving to a
battery with higher amperage ratings. On a stock AK47, the difference in
using a LARGE 8.4v 1700mah battery and a LARGE 8.4v 2000mah battery is quite
apparent; the 2000mah battery drives the BB's out at a much higher rate (can
you say "Bullet Hose"?)!

Alright, so does this mean that you should go
out and get a 9.6v 3000mah battery with M150 spring and EG1000 motor?

Absolutely not!Overdoing it will strip your gears and wear down your AEG
unnecessarily. Due to the design of AEGs, you cannot run the motor too
fast, and driving an EG1000 with a 9.6v 3000mah (or even an 8.4v) battery
would translate into instantly stripped gears before you can even get your
first 10 shots off! However if you've installed an upgraded spring,
the extra resistance on the motor will allow you to go up one notch on the
battery scale and still be relatively safe. Sound confusing? It
is and there really isn't a set guideline as to what works and what doesn't
- that's the beauty of it all - you should trial and error to see what
combination fits your needs the best.

Here's a table based on our own experience to
guide you on what's reasonably safe:

EG560*

EG700

EG1000

M90
(stock)

9.6v
2300mah (max)

8.4v
2300mah (max)

8.4v
2000mah (max)

M100

-

9.6v
2000mah (max)
8.4v 2000mah (recommended)

8.4v
2000mah (max)

M120

-

9.6v
2000mah (max)
8.4v 2300mah (recommended)

8.4v
2300mah (max)

M130

-

9.6v
2300mah (max)
8.4v 2300mah (recommended)

8.4v
2300mah (max)

M140

-

9.6v
3000mah (max)
8.4v 3000mah (recommended)

8.4v
2300mah (max)

M150

-

9.6v
3000mah (max)
8.4v 3000mah (recommended)

8.4v
3000mah (max)
12v 600mah (recommended for M4A1)

Disclaimer: The maximum
recommended battery ratings are based on experience at RedWolf
airsoft. Actual maximum's may vary depending on the
"mileage" of the AEG being modified and the gearbox type in
question. The reader should be aware that ANY upgrade will increase
wear-and-tear on AEGs and you should not expect an upgraded AEG to be as
durable or even last as long as a stock AEG under sustained use.
* Notice that the entire column for EG560
is "-" for anything above a stock spring. As I mentioned
above, ANY spring upgrade would invalidate the EG560.

Also note that we typically don't encourage
use of 9.6v batteries. The reason is that the power is driven up
quite a bit and unless you have a very highly rated spring - otherwise the
9.6v battery may provide too much power and leave you with stripped gears -
it's like revving an engine too high for too long a time beyond redline. LARGE 9.6v batteries also tend to cause carbonization at the
motor brush contacts and may require more meticulous maintenance to keep
things running smoothly in the long term.

So in summary, here are some basic rules to
remember.

1. AEG Upgrades require use of large batteries or custom batteries
2. More voltage and current translates into more torque and higher rate of fire
3. EG1000 motors have more torque by nature than EG700 motors so you may not need to feed an EG1000 with too much voltage and current to achieve maximum performance
4. LARGE 9.6v batteries (ie with amperage of 1700mah or more) tend to wear out motors quicker
5. More is not always good. There is a limit to what you can match up in terms of motor, battery, and spring. Too much good stuff will strip your gun!

For a full list of batteries that we carry, check out our accessories section.